Discrete-dipole approximation with polarizabilities that account for both finite wavelength and target geometry

Abstract

The discrete-dipole approximation (DDA) is a powerful method for calculating absorption and scattering by targets that have sizes smaller than or comparable to the wavelength of the incident radiation. We present a new prescription -- the Surface-Corrected Lattice Dispersion Relation (SCLDR) -- for assigning the dipole polarizabilities that takes into account both target geometry and finite wavelength. We test the SCLDR in DDA calculations using spherical and ellipsoidal targets and show that for a fixed number of dipoles, the SCLDR prescription results in increased accuracy in the calculated cross sections for absorption and scattering. We discuss extension of the SCLDR prescription to irregular targets.

14 pages, 7 color figures, LaTeX, uses osajnl.sty and overcite.sty, submitted to JOSA A

References in corpus (1)

• Propagation of Electromagnetic Waves on a Rectangular Lattice of Polarizable Points

Cited by in corpus (9)

• The discrete dipole approximation: an overview and recent developments
• Modeling Porous Dust Grains with Ballistic Aggregates I: Geometry and Optical Properties
• Convergence of the discrete dipole approximation. I. Theoretical analysis
• Convergence of the discrete dipole approximation. II. An extrapolation technique to increase the accuracy
• Convergence analysis of the thermal discrete dipole approximation
• Graphite Revisited
• Scattering from rough thin films: DDA-simulations
• Light Scattering and Thermal Emission by Primitive Dust Particles in Planetary Systems
• Sensitivity of Polarization to Grain Shape: I. Convex Shapes